isolate podofo to prepare for native parser, autogenerate PDF API during build

experimental/PdfViewer/pdfparser/podofo/SkPdfPodofoTokenizer.h

+#ifndef EXPERIMENTAL_PDFVIEWER_PDFPARSER_PODOFO_SKPDFPODOFOTOKENIZER_H_
+#define EXPERIMENTAL_PDFVIEWER_PDFPARSER_PODOFO_SKPDFPODOFOTOKENIZER_H_
+
+#include "stddef.h"
+
+class SkPdfObject;
+class SkPdfMapper;
+class SkPodofoParsedPDF;
+
+namespace PoDoFo {
+class PdfMemDocument;
+class PdfContentsTokenizer;
+}
+
+enum SkPdfTokenType {
+    kKeyword_TokenType,
+    kObject_TokenType,
+    kImageData_TokenType,  // TODO(edisonn): inline images seem to work without it
+};
+
+struct PdfToken {
+    const char*      fKeyword;
+    SkPdfObject*     fObject;
+    SkPdfTokenType   fType;
+
+    PdfToken() : fKeyword(NULL), fObject(NULL) {}
+};
+
+class SkPdfPodofoTokenizer {
+public:
+    SkPdfPodofoTokenizer(const SkPodofoParsedPDF* parser, PoDoFo::PdfContentsTokenizer* tokenizer);
+    SkPdfPodofoTokenizer(const SkPdfObject* objWithStream);
+    SkPdfPodofoTokenizer(const char* buffer, int len);
+
+    virtual ~SkPdfPodofoTokenizer();
+
+    bool readToken(PdfToken* token);
+    bool readTokenCore(PdfToken* token);
+    void PutBack(PdfToken token);
+
+private:
+    const SkPdfMapper* fMapper;
+    const PoDoFo::PdfMemDocument* fDoc;
+    PoDoFo::PdfContentsTokenizer* fTokenizer;
+
+    char* fUncompressedStream;
+    long fUncompressedStreamLength;
+
+    bool fEmpty;
+    bool fHasPutBack;
+    PdfToken fPutBack;
+};
+
+#endif  // EXPERIMENTAL_PDFVIEWER_PDFPARSER_PODOFO_SKPDFPODOFOTOKENIZER_H_